ActivityNet-v1.3  [1]} is a large-scale video dataset for action recognition and temporal action detection tasks.
It contains 10K training, 5k validation, and 5k testing videos with 200 action categories, and the ratio of training, validation and testing sets is 2:1:1.
THUMOS14 [2]} contains 200 validation untrimmed videos and 213 test untrimmed videos, including 200 action categories.
This dataset is challenging due to the large variations in the frequency and duration of action instances across videos.
